Tubular goods and liners

ABSTRACT

Disclosed herein are tubular goods and tubular good liners which decrease or eliminate friction and mechanical wear and decrease or eliminate chemical corrosion to the walls of the tubular good. The liners may include a diffusion barrier, an adhesive, and a friction and wear resistant layer.

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 60/367,132, filed May 16, 2002, incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable

BACKGROUND

[0003] Tubular goods, such as oil country tubular goods (“OCTG's”) (e.g., well casing, tubing, drillpipe, drill collars, and line pipe) and flowline tubular goods, are often used for transportation of gases, liquids, and mechanical equipment, including various applications related to extraction of petroleum and natural gas from underground reservoirs, transportation of petroleum, natural gas, and other materials, such as solution mining and slurry transport lines in the mining industry. OCTG's may be used to transport the product from the underground reservoir, and also to house mechanical equipment (e.g., artificial lift devices, rod couplings, plungers, reciprocating rod pumping units, rotating progressive cavity pumps, and plunger lift units), electrical equipment (e.g., well monitoring equipment), and/or transport gases or liquids for disposal operations or secondary removal operations. These gases and liquids may contain corrosive materials such as, by way of example only, salt water, dissolved oxygen, CO₂, or H₂S. In addition, flowline tubular goods may be used to transport petroleum, petroleum products, natural gas, or other gases or liquids from one point to another. The gases and liquids which flow within flowlines may, comprise corrosive and/or abrasive components. In addition, flowline tubular goods may also occasionally require the use of mechanical equipment, such as pigs, to clean or service the tubular good.

[0004] With respect to moving mechanical equipment and abrasive fluids, such as reciprocating or rotating rods or pumps or drilling or mining slurries (e.g., drilling mud), friction and abrasion may cause wear, fatigue, and even failure of the pipe and/or the equipment. In addition, this wear, fatigue, or failure may be accelerated due to the presence of corrosive or abrasive materials, such as, for example CO₂, or by deviations in the direction of the well bore. One method of combatting this wear in oil well production equipment is disclosed in U.S. Patent No. RE36,362 to Jackson, incorporated herein by reference.

[0005] In addition to the possible acceleration of mechanical wear, fatigue, and failure, the presence of corrosive material, in and of itself, may cause chemical damage to the OCTG's and flowline tubular goods. By way of example only, the presence of CO₂, when contacted with metal or other materials may cause corrosion, dusting, rusting, or pitting, which may lead to failure of the material. In addition, the presence of microbiological active agents, such as bacteria, may produce chemicals which influence or accelerate corrosion.

[0006] It would therefore be desirable to create tubular goods which decrease or eliminate the mechanical and/or chemical wear, fatigue, or failure caused by the conditions surrounding the extraction of materials such as petroleum or natural gas and transportation of materials, thereby potentially increasing the life and productivity of the tubular good.

SUMMARY

[0007] Disclosed herein are methods and apparatus for reducing or eliminating the mechanical and/or chemical wear, fatigue, and failure on tubular goods. The methods comprise disposing a liner along at least a portion of the tubular good. The liner may decrease friction, thereby decreasing mechanical wear as well as reducing the amount of energy necessary to operate the mechanical tool or pump the abrasive fluid. In addition, the liner may also comprise a material which is resistant to particular chemicals or a barrier to particular chemicals, thereby decreasing or eliminating contact between the chemicals and the tubular good and decreasing or eliminating the wear or corrosion caused by those chemicals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a schematic drawing of a tubular good in accordance with embodiments of the present invention.

[0009]FIG. 2 is a cross section of a tubular good in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

[0010] Referring now to FIG. 1, there is shown metal tubing 30, coupling 36, and liner 40. Two joints of metal tubing 30, having an inner diameter 32 and outer diameter 34, are connected together by coupling 36. Disposed within each tubing joint 30 adjacent to its inner surface 38 is a liner 40 (an embodiment of which is shown in detail in FIG. 2). Liner 40 may be a multilayer system comprising both a wear resistant material and a diffusion barrier. In some embodiments, where gas diffusion is of minimal or no concern, liner 40 may comprise a layer comprising only a wear barrier such as polypropylene with no diffusion barrier being present.

[0011] The liner 40 may be disposed within the tubing 30 by any one of several methods known in the art. One method of disposing the liner within the tubing bore is to provide a polymer liner having an outside diameter which is slightly greater than or equal to the inner diameter of the tubing section pipe having an outside diameter larger than the internal diameter of the tubing. Reduce the outside of the liner and insert the reduced diameter liner within the tubing. After the liner is in place, it will attempt to substantially return to its original shape and will become secured within the tubing section via process called plastic deformation. There may be numerous methods of reducing the outside diameter of the liner for insertion into a tubing section are available. For example, rollers may be used to mechanically reduce the outside diameter of the liner by the desired amount and to push the liner into the tubing joint. Other methods include pulling the liner through a sizing sleeve or orifice and pushing the reduced diameter liner into place in the tubing.

[0012] One method of disposing the polymer liners within the tubing sections includes providing a liner having an initial outside diameter similar to or larger than the inner diameter of the tubing, reducing the outer diameter of the liner by mechanical means and inserting the liner into the tubing bore. The ends of the polymer liner may then be softened using a heat source and formed around the end of the external pipe thread on the metal pipe. In some cases, the ends may be reinforced for additional structural integrity. The ends may then be joined onto a coupling (with or without an internal coating or corrosion resistant insert) used to join each stick of lined pipe. The process ultimately provides a one-piece seamless liner in each joint that is mechanically bonded to the metal pipe ID. The wall thickness of the claimed liners is preferably between about 2 and 10 millimeters. The diameter of the claimed liners may be between about 20 and 700 millimeters or greater. In the embodiments shown in FIG. 1, the thickness “t” of the liner 40 is about 4 millimeters.

[0013] Referring now to FIG. 2 (not to scale), there is shown lined tubular good 100 comprising outer layer 110, diffusion barrier 120, adhesive layers 130 and 160 (optional), and friction and wear reducing layers 140 and 150 outer layer 110 may be a metal tubular good such as an OCTG, a flowline tubular good, or a solution mining or slurry transport line. The tubular good liner is preferably comprised of elements 120, 130, 140, 150, and 160. Friction and wear reducing layers 140 and 150 may comprise, by way of example only, polyethylene or polypropylene. Layers 140 and 150 may or may not consist of the same material. Diffusion reducing layer may comprise, by way of example only, a vinyl alcohol such as polyvinyl alcohol. Layer 140 may be bonded to diffusion barrier 120 by any method as would be appreciated by one of skill in the art. By way of example only, layers 120 and 140 may be bonded by adhesive layer 130 and layers 150 and 120 may be bonded by adhesive layer 160. Adhesive layers 130 and 160 may be, but are not necessarily, the same adhesive. Adhesive layers 130 and 160 may comprise, any acceptable polymer adhesive as is known in the art, such as copolymers.

[0014] In addition, layers 120 and 140 may be bonded by the addition of additives to the layers, by way of example only, 2,5-furandione, the chemical structure of which is set forth as Formula 1 below:

[0015] when added to the layers may cause the layers to become bonded together without the need for additional adhesives.

[0016] The layers are typically coextruded through a specially designed extrusion die head using multiple extruders. The melted polymer layers are then cooled into one continuous seemless tube.

[0017] While embodiments of the invention have been described herein, it will be recognized and understood that various modifications may be made and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention. By way of example only, the friction and wear reducing layer may comprise nucleated polypropylene; polyolefins containing nanocomposites or other additives to control diffusion rates; impact copolymer grade polypropylene; homopolymer grade polypropylene; heterophasic copolymers; fractional melt grade polypropylene; other thermoplastics coextruded with polypropylene; reactor made thermoplastic polyolefins; metallocene catalyzed polypropylenes; random copolymer polypropylenes; blends, alloys, filled or reinforced polypropylene or polyethylene containing other polyolefins and structural reinforcement. In addition, additives may be included in the polymer to increase the lubricity of the liner material and decrease the coefficient of friction of the product.

[0018] The gas diffusion barrier may comprise other polymers, organic or inorganic materials, or metals. In some embodiments, this barrier is chosen to reduce or eliminate the permeation of carbon dioxide through liners utilized in CO₂ floods and WAG (water-alternating-gas) injection systems for oil production enhanced recovery operations.

[0019] In embodiments in which the friction wear reducing layer and the diffusion barrier are chemically bonded 2,5-furandione or other similar additives may be used. The layers may also be bound by any acceptable adhesive as is known in the art. For example, an acceptable adhesive may comprise a copolymer. It is also envisioned that the friction wear reducing layer and the diffusion barrier need not be directly bonded together. There may be intermediate layers between the two. Additionally, there may be layers radially outward or inward of the diffusion barrier. By way of example only, the diffusion barrier may be sandwiched between the friction and wear reducing layer and a third layer. The third layer may be of the same or different material as the friction and wear reducing layer. 

1. A tubular good comprising: an outer pipe layer; and an inner layer, wherein the inner layer comprises a diffusion barrier and a friction reducing layer, and wherein the diffusion barrier is disposed radially outward of the friction reducing layer.
 2. The tubular good of claim 1 further comprising an adhesive layer disposed between the diffusion barrier and the friction reducing layer.
 3. The tubular good of claim 1 wherein the tubular good is an oil country tubular good.
 4. The tubular good of claim 1 wherein the tubular good is a flowline tubular good.
 5. The tubular good of claim 1 wherein the diffusion barrier comprises a vinyl alcohol.
 6. The tubular good of claim 1 wherein the friction reducing layer comprises a polyolefin.
 7. The tubular good of claim 1 wherein the compound represented by the following formula:

is used as an additive to bond the diffusion barrier and the friction reducing layer.
 8. The tubular good of claim 1 wherein the friction reducing layer comprises polyethylene.
 9. The tubing good of claim 1 wherein the friction reducing layer comprises a homopolymer.
 10. The tubing good of claim 1 wherein the friction reducing layer comprises a copolymer.
 11. The tubing good of claim 1 wherein the friction reducing layer comprises polypropylene.
 12. The tubing good of claim 1 further comprising a third layer radially outward from the diffusion barrier and radially inward from the outer pipe layer.
 13. A method of preparing a tubular good, the method comprising: providing an outer tubular layer; providing an inner tubular layer; wherein the inner tubular layer comprises a chemical barrier and a wear reducing layer; wherein the chemical barrier is disposed radially outward from the wear reducing layer; inserting the inner tubular layer into the outer tubular layer.
 14. The method of claim 13 further comprising bonding the chemical barrier to the wear reducing layer.
 15. The method of claim 13 further comprising providing an adhesive layer disposed between the chemical barrier and the wear reducing layer, wherein the adhesive layer bonds the chemical barrier to the wear reducing layer.
 16. The method of claim 14 wherein the compound represented by the following formula:

is used as an additive to bond the diffusion barrier and the friction reducing layer.
 17. The method of claim 13 wherein the wear reducing layer comprises a polyolefin.
 18. The method of claim 13 wherein the wear reducing layer comprises polyethylene.
 19. The method of claim 13 wherein the diffusion barrier comprises a vinyl alcohol.
 20. The method of claim 13 wherein the wear reducing layer comprises a copolymer.
 21. The method of claim 13 wherein the wear reducing layer comprises polypropylene.
 22. The method of claim 13 wherein the wear reducing layer comprises a homopolymer.
 23. The method of claim 13 further comprising providing a third layer wherein the third layer is disposed radially outward from the diffusion barrier and radially inward from the outer tubular layer.
 24. A tubular good liner comprising: a wear barrier; and a diffusion barrier; wherein the diffusion barrier is disposed radially outside of the wear barrier; and wherein the diffusion barrier is bonded to the wear barrier.
 25. The tubular good of claim 24 further comprising an adhesive layer bonding the wear barrier to the diffusion barrier.
 26. The tubular good liner of claim 24 wherein the compound represented by the following formula:

is used as an additive to bond the diffusion barrier and the friction reducing layer.
 27. The tubular good liner of claim 24 wherein the wear barrier comprises polyethylene.
 28. The tubular good liner of claim 24 wherein the wear barrier comprises polypropylene.
 29. The tubular good liner of claim 24 wherein the diffusion barrier comprises a vinyl alcohol.
 30. The tubular good liner of claim 24 wherein the wear barrier comprises a homopolymer.
 31. The tubular good liner of claim 24 wherein the wear barrier comprises a copolymer.
 32. The tubular liner of claim 24 further comprising a third layer disposed radially outward from the diffusion barrier.
 33. A tubular good liner comprising: a means for reducing friction; a means for preventing diffusion of a compound; and a means for bonding the means for reducing to the means for preventing; wherein the means for preventing is disposed radially outward from the means for reducing.
 34. A tubular good liner comprising polypropylene.
 35. The tubular good liner of claim 34 wherein the tubular good is an oil country tubular good.
 36. The tubular good liner of claim 34 wherein the tubular good is a flowline tubular good.
 37. The tubular good liner of claim 34 wherein the tubular good is a slurry transport line.
 38. The tubular good liner of claim 34 wherein the tubular good is a solution mining tubular good.
 39. The tubular good liner of claim 34 wherein the tubular good houses a reciprocating member.
 40. The tubular good liner of claim 34 wherein the tubular good contains a rotating member.
 41. The tubular good liner of claim 34 wherein the tubular good transports abrasive material.
 42. A method for producing well fluids: providing a rod pumping system comprising at least one sucker rod disposed within a string of tubing which extends into said well, the string of tubing comprising at least one tubing section having a bore and an inside diameter; a down hole pump operably connected to the at least one sucker rod; and means for reciprocating the at least one sucker rod; wherein a liner comprising polypropylene is disposed within the bore of the tubing to eliminate or reduce contact between the at least one sucker rod and the tubing string. 